Conventional time domain multiple access (TDMA) satellite communication networks employ multiple radio stations which communicate through an earth satellite repeater by transmitting time-synchronized bursts of radio energy relative to the repeater and which receive a time multiplex composite of bursts containing corresponding modulated information from the repeater. In TDMA operations, multiple ground stations associated with radio signaling nodes transmit bursts of time-concentrated information signals on a shared carrier frequency spectrum and receive the same information signals after repetition by the satellite repeater on a shifted carrier frequency spectrum. Each ground station is assigned a particular time slot in a continuum of recurrent frames for transmission of its bursts and for the reception of its own bursts and the bursts of other stations. The bursts interleave at the satellite in close time formation without overlapping. Each earth station includes connections to incoming digital lines originating from terrestrial sources. These input lines are respectively connected to digital data ports on a satellite communications controller (SCC) at the station.
Prior art techniques for testing the operation of communications controllers typically employ complex, large scale equipment having specialized components dedicated to each data rate element of the communications controller which must be tested. In addition, the communications controller must be taken off line from handling ordinary traffic in order to carry out component testing, in the prior art. One example, of the prior art discloses a service generator checking apparatus in a telephone system operating in time division multiple access mode. The apparatus sends a tone sample signal in one frame through a system interface having an input portion and an output portion, and compares the sent tone sample signal with a stored sample in a subsequent frame, thereby verifying that the interface is operational. However, the system does not maintain a continuous flow of communication while the test is being performed and the tester cannot accommodate a system having several different communication rates.